As a vital component of power electronic transformers (PET), the reliability of a cascaded H-bridge rectifier (CHBR) is essential. Therefore, in this paper, a DC-port voltage balance strategy considering DC-port failure is researched to ensure the stable operation of a CHBR. However, if the DC-port voltage balance strategy is adopted to realize the single-phase balance of a CHBR, the three-phase currents become unbalanced. This paper uses a negative sequence control (NSC) strategy that is conducive to balancing DC-port voltage to achieve three-phase current balance. For the DC-port voltage balance, the matrix generation modulation (MGM) algorithm is proposed. In addition, the DC-port voltage balance boundary is analyzed to determine the range of the DC-port voltage balance in the CHBR. A 3-module cascading topology is adopted to demonstrate the MGM algorithm and the NSC strategy. Through experiments, results show the correctness and feasibility of the proposed strategy.

作为电力电子变压器 (PET) 的重要组成部分，级联 H 桥整流器 (CHBR) 的可靠性至关重要。因此，本文研究了一种考虑DC端口故障的DC端口电压平衡策略，以保证CHBR的稳定运行。但是，如果采用直流端口电压平衡策略来实现CHBR的单相平衡，则三相电流会变得不平衡。本文采用有利于平衡直流端口电压的负序控制（NSC）策略实现三相电流平衡。对于直流端口电压平衡，提出了矩阵生成调制（MGM）算法。此外，通过分析DC端口电压平衡边界，确定CHBR中DC端口电压平衡的范围。采用3模块级联拓扑来演示MGM算法和NSC策略。通过实验，结果表明了所提策略的正确性和可行性。